Question

Using the dataset that you used for the midterm (Find it on the Blackboard), do the following:

1) (4 points) Submit the values for items a to e in the table below: mean, sample size, standard deviation, and 95% confidence interval for mean. (SPSS Command: Analyze/Descriptive Statistics/Explore)

Variable			Statistic
Height	Mean		71.2
	Sample Size N		999
	Standard Deviation		2.913
	95% Confidence Interval for Mean	Lower Bound	71.02
		Upper Bound	71.38

2) (4 points) Assume that you want to test whether the average height (the population mean μ) is less than 72 inches. Write down in both symbols and words the null hypothesis and alternative hypothesis.

2) (6 points) What type of significance test should you use to test your hypothesis? Write down the test statistic formula, and calculate the value of the test statistic. (Hint: Plug the sample standard deviation into the test statistic formula in place of the population standard deviation.)

3) (4 points) Find the P-value. [Use Table A: Standard Normal probabilities]

4) (3 points) At level of significance of 0.05 (5%), explain what conclusion you can draw about the hypothesis.

5) (8 points) Use SPSS to conduct the following significance test: H0: μ =72 vs. Ha: μ≠72. [Use SPSS Analyze/Compare Means/One Sample T-test/Set Test Value to 72.] What type of significance test is this? Report the value of the test statistic (“t”-statistic) and the corresponding P-value (“Sig.” level) that SPSS provides. Suppose the level of significance you chose for your test is the conventional 0.05 (5%), explain what conclusion you can draw about the hypothesis.

Answer 1

3 又一72 . 0 G8 되